[Home] Use separate toolbar shadow for Chrome Modern

Other varieties of the toobar depend on the shadow drawable not
changing. This change reverts the bottom_toolbar_shadow to its
original state (crrev.com/c/646428) and creates a separate one for
Chrome Modern.

BUG=

Change-Id: I3b7964cf603df1308a00942cd728726d5268f71c
Reviewed-on: https://chromium-review.googlesource.com/660984
Commit-Queue: Matthew Jones <mdjones@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#501332}

chrome/android/java/res/drawable/bottom_toolbar_shadow.xml

@@ -2,15 +2,23 @@
 <!-- Copyright 2017 The Chromium Authors. All rights reserved.
      Use of this source code is governed by a BSD-style license that can be
      found in the LICENSE file. -->
+
+<!-- ToolbarPhone uses this drawable to transition between shadows when
+     the omnibox focus changes. The bottom toolbar should not have a shadow
+     when the omnibox is unfocused so this TransitionDrawable uses an empty
+     shape for the focused drawable item.
+     TODO(twellington): Remove this after UX has a spec'ed out what the
+     bottom toolbar omnibox un/focus animations should look like. -->
 <transition xmlns:android="http://schemas.android.com/apk/res/android">
     <item>
-        <bitmap
-            android:src="@drawable/toolbar_shadow_focused"
-            android:gravity="top|fill_horizontal" />
+        <shape
+            android:shape="rectangle"
+            android:gravity="top|fill_horizontal" >
+        </shape>
     </item>
     <item>
         <bitmap
-            android:src="@drawable/bottom_toolbar_top_line"
+            android:src="@drawable/toolbar_shadow_focused"
             android:gravity="top|fill_horizontal" />
     </item>
 </transition>

chrome/android/java/res/drawable/modern_bottom_toolbar_shadow.xml

+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2017 The Chromium Authors. All rights reserved.
+     Use of this source code is governed by a BSD-style license that can be
+     found in the LICENSE file. -->
+<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
+    <item>
+        <bitmap
+            android:src="@drawable/toolbar_shadow_focused"
+            android:gravity="top|fill_horizontal" />
+    </item>
+    <item>
+        <bitmap
+            android:src="@drawable/bottom_toolbar_top_line"
+            android:gravity="top|fill_horizontal" />
+    </item>
+</layer-list>

chrome/android/java/src/org/chromium/chrome/browser/toolbar/BottomToolbarPhone.java

@@ -300,7 +300,7 @@ public class BottomToolbarPhone extends ToolbarPhone {
         mBottomToolbarTopShadow =
                 (ImageView) getRootView().findViewById(R.id.bottom_toolbar_shadow);
         mBottomToolbarTopShadowDrawable = (LayerDrawable) ApiCompatibilityUtils.getDrawable(
-                getResources(), R.drawable.bottom_toolbar_shadow);
+                getResources(), R.drawable.modern_bottom_toolbar_shadow);
 
         mBottomToolbarTopShadowDrawable.getDrawable(0).setAlpha(255);
         mBottomToolbarTopShadowDrawable.getDrawable(1).setAlpha(0);